The experimental program will be directed toward an elucidation of the factors which regulate ammonia synthesis by the mammalian kidney. The proposed studies will be performed utilizing isolated renal cortical mitochondria to obtain kinetic data defining the characteristics of glutamine and glutamate transport across the mitochondrial membrane. Further studies will be carried out to relate the accelerated rate of glutamate dehydrogenase flux occurring in acidosis to protein synthesis and glutamate channeling within the matrix space. The mechanism of inhibition of glutamate deamination and glutamine deamidation by alpha-ketoglutarate will be investigated in detail. Utilizing cell fractionation methods, analysis of metabolite profiles in cytosolic and mitochondrial compartments of isolated renal tubules will be performed to provide further insight into alterations in renal metabolism in acidosis. The role of adrenal steroids in renal glutamine and glutamate metabolism will also be investigated, utilizing isolated mitochondria and the isolated perfused kidney preparation. These studies will be extended to kidney mitochondria from uremic rats. These studies will provide further insight into the biochemical mechanisms underlying the control of renal ammoniagenesis.